Field of the Invention
The invention relates generally to folding steps to facilitate access to elevated spaces, and more particularly to folding steps that are adapted to be mounted to a wall above an adjacent floor.
Prior Art
Campers by their very nature must economize space and allow easy access to all living and storage spaces, some of which may be relatively high above the truck bed which supports the main floor of the camper. In some cab-over campers, a large step having an interior storage compartment provides able bodied adults access to a sleeping compartment above the truck cab.
Folding steps have been built into cabinets used in kitchens and other cramped areas to allow shorter persons safe access to upper shelves and storage compartments. Such steps fold away when not used to economize living space.
U.S. Pat. No. 1,953,298 (Goodwin) and U.S. Pat. No. 2,158,949 (Sarles) disclose steps that unfold from walls supported by a single hinge attached to the wall. These cantilevered designs require walls capable of withstanding significant shear forces and the single hinge must be able to withstand significant torque to support the weight of the person (typically a child or small adult) using the step.
U.S. Pat. No. 5,085,290 (Guirlinger), U.S. Pat. No. 3,136,386 (Horvath), U.S. Pat. No. 3,030,166 (Richards) and U.S. Pat. No. 5,131,492 (Caminiti) all disclose step assemblies that unfold from a wall and which include vertical floor engaging members that are designed to support the weight of a large adult. Provided it is maintained in a vertical position, the support from the floor engaging members reduces the requirement of the wall to withstand significant shear forces and reduces the requirement of the attached hinge to withstand significant torque.
U.S. Pat. No. 3,166,277 (Brison) and U.S. Pat. No. 5,094,515 (Low) disclose step assemblies that unfold from the wall and are intended to support the weight of a large adult. The Brison device comprises tracks that must be mounted to the wall to support and align the step and the supporting member. The Low device comprises a vertical floor engaging member to support the weight.